If im online and I start Outlook my connection shuts off then redials whats up?
What did make you think this is avast related?
avast does not have a dialer or a connection killer feature...
For me, that seems to be an Outlook setting (are you talking about MS Outlook, not Express, aren't you?).
Is Outlook set to download email messages when starts?
Can you disable/enable the avast! plugin into Outlook? (About dialog of Outlook)?
Try to find out what program or service is trying to connect. If you have windows XP, check the system log files. They might give you a clue.